8,736 research outputs found
Dressed projectile charge state dependence of differential electron emission from Ne atom
We study the projectile charge state dependence of doubly differential electron emission cross section (DDCS) in ionization of Ne under the impact of dressed and bare oxygen ions. Experimental DDCS results measured at different angles are compared with the calculations based on a CDW-EIS approximation using the GSZ model potential to describe projectile active-electron interaction. This prescription gives an overall very good agreement. In general a deviation from the q2-law was observed in the DDCS. The observations crudely identify the dominance of different projectile electron loss mechanisms at certain electron energy range.Fil: Biswas, S.. Tata Institute of Fundamental Research; IndiaFil: Monti, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Tribedi, L. C.. Tata Institute of Fundamental Research; Indi
The use of ultrasound in clinical setting for children affected by NAFLD. is it safe and accurate?
Non-alcoholic fatty liver disease (NAFLD) has become over the last decade the most common form of chronic liver disease in children and adults. Thus, establishing the diagnosis of NAFLD is of utmost importance and represents a major challenge as the disease is generally silent and the current gold standard for diagnosis is an invasive liver biopsy, a procedure that is not suitable for screening purposes. Many non-invasive diagnostic tools have been evaluated so far. Recently the utility of ultrasonography for non-invasive diagnosis and estimation of hepatic steatosis has been demonstrated in a large prospective pediatric study
Optimization of force-limiting seismic devices connecting structural subsystems
This paper is focused on the optimum design of an original force-limiting floor anchorage system for the seismic protection of reinforced concrete (RC) dual wall-frame buildings. This protection strategy is based on the interposition of elasto-plastic links between two structural subsystems, namely the lateral force resisting system (LFRS) and the gravity load resisting system (GLRS). The most efficient configuration accounting for the optimal position and mechanical characteristics of the nonlinear devices is obtained numerically by means of a modified constrained differential evolution algorithm. A 12-storey prototype RC dual wall-frame building is considered to demonstrate the effectiveness of the seismic protection strategy
Sequential electron transfer in the primary photosynthetic reaction of Rhodobacter sphaeroides
Characterization of DNA methylation as a function of biological complexity via dinucleotide inter-distances
We perform a statistical study of the distances between successive
occurrencies of a given dinucleotide in the DNA sequence for a number of
organisms of different complexity. Our analysis highlights peculiar features of
the dinucleotide CG distribution in mammalian DNA, pointing towards a
connection with the role of such dinucleotide in DNA methylation. While the CG
distributions of mammals exhibit exponential tails with comparable parameters,
the picture for the other organisms studied (e.g., fish, insects, bacteria and
viruses) is more heterogeneous, possibly because in these organisms DNA
methylation has different functional roles. Our analysis suggests that the
distribution of the distances between dinucleotides CG provides useful insights
in characterizing and classifying organisms in terms of methylation
functionalities.Comment: 13 pages, 5 figures. To be published in the Philosophical
Transactions A theme issue "DNA as information
Presence and conservation of the immunoglobulin superfamily in insects: current perspective and future challenges
Numerous proteins that contain a bona fide immunoglobulin domain have been identified in the
last decade showing that immunoglobulin-like proteins are quite common in metazoans. In particular,
recent surveys identified more than 140 immunoglobulin-like proteins in Drosophila melanogaster,
Anopheles gambiae and Bombyx mori. A well-studied example of immunoglobulin-like protein is the
Drosophila Down syndrome cell adhesion molecule (Dscam) that, accordingly to comparative
molecular analyses, showed a high conservation in Diptera, Hymenoptera and Coleoptera, together
with a conserved presence of alternative splicing that permitted insects to possess an unsuspected
molecular complexity of their innate immune system. At a functional level, immunoglobulin-like
proteins seem to be capable of reacting to pathogen challenges and may contribute to the defense
against infection so that they are candidates as immune effector molecules in insects. Preliminary
findings on insect-borne plant and animal diseases suggest a possible role of the immunoglobulin-like
proteins in the vectorial capacity
Non-minimality of corners in subriemannian geometry
We give a short solution to one of the main open problems in subriemannian
geometry. Namely, we prove that length minimizers do not have corner-type
singularities. With this result we solve Problem II of Agrachev's list, and
provide the first general result toward the 30-year-old open problem of
regularity of subriemannian geodesics.Comment: 11 pages, final versio
Monitoring urban heat island through google earth engine. Potentialities and difficulties in different cities of the United States
The aim of this work is to exploit the large-scale analysis capabilities of the innovative Google Earth Engine platform in order to investigate the temporal variations of the Urban Heat Island phenomenon as a whole. A intuitive methodology implementing a large-scale correlation analysis between the Land Surface Temperature and Land Cover alterations was thus developed. The results obtained for the Phoenix MA are promising and show how the urbanization heavily affects the magnitude of the UHI effects with significant increases in LST. The proposed methodology is therefore able to efficiently monitor the UHI phenomenon
Quasi-equilibrium states in thermotropic liquid crystals studied by multiple quantum NMR
We study the nature of the quasiinvariants in nematic 5CB and measure their
relaxation times by encoding the multiple quantum coherences of the states
following the JB pulse pair on two orthogonal bases, Z and X. The experiments
were also performed in powder adamantane at 301 K which is used as a reference
compound having only one dipolar quasiinvariant. We show that the evolution of
the quantum states during the build up of the quasi-equilibrium state in 5CB
prepared under the S condition is similar to the case of adamantane and that
their quasi-equilibrium density operators have the same tensor structure. In
contrast, the second constant of motion, whose explicit operator form is not
known, involves a richer composition of multiple quantum coherences on the X
basis of even order, in consistency with the truncation inherent in its
definition. We exploited the exclusive presence coherences 4, 6, 8, besides 0
and 2 under the W condition to measure the spin-lattice relaxation time T_{W}
accurately, so avoiding experimental difficulties that usually impair dipolar
order relaxation measurement such as Zeeman contamination at high fields, and
also superposition of the different quasiinvariants. This procedure opens the
possibility of measuring the spin-lattice relaxation of a quasiinvariant
independent of the Zeeman and S reservoirs, so incorporating a new relaxation
parameter useful for studying the complex molecular dynamics in mesophases. In
fact, we report the first measurement of T_{W} in a liquid crystal at high
magnetic fields. The comparison of the obtained value with the one
corresponding to a lower field (16 MHz) points out that the relaxation of the
W-order strongly depends on the intensity of the external magnetic field,
similarly to the case of the S reservoir, indicating that the relaxation of the
W-quasiinvariant is also governed by the cooperative molecular motions.Comment: 7 figures. http://www.famaf.unc.edu.ar/series/AFis2005.ht
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